Combined hydromechanical gear



Filer; Aug. S," 1941 j 4s'nss-sheet 1 VFRITZ KUGEL.

' HELMUTBENZ Ow 2 man.

Jan. s, 1946.

H. BENZ ET AL COMBINED HYDRO-ME GHANICAL GEAR Filed Aug. 5, 1941 4 Sheets-Sheet 2 .TM FRITZ KUGEL HELMUT BENZ, OM

H. BENZ ETAL 2,392,520 i COMBINED HYDRO -MECHANI CAL GEAR Jan. s, 1946,

4 Sheets-Sheet 3 Filed Aug. 5, 1941 H. BENZ ET AL COMBINED HYDRO-MECHANICAL GEAR Jan. 8, 1946.

Filed Aug. 5, 1941 4 sheets-sheet 4 UNITED` STATES PATENT OFFICE COMBINED HYDROMECHANICAL GEAR Helmut Benz ana Fritz "Kugel, Heidenheim, Brenz, Germany; vested in the Alien Property Custodian l f Application August 5, 1941, Serial No. 405,540 In Germany August 8, 1940v 7 Claims. (Cl. 74189.5) i

This invention relates to power transmissions also present with a converter having an annular and, in particular, to hydromechan'ical compound slide valve or shiftable blades. power transmissions comprising a hydraulic The'torque converter with disconnecting mechtransmission and a gear change transmission sys anism therefore constitutes an extremely adapttem. The hydraulic transmission may comprise able element which makes it possible to create, at one or a plurality ofhydraulic circuits, which the output shaft of the torque converter, any may be torque converters or couplings. 'I'he gear ldesired torque between a full positive value and system for such a combination usually has posia small negative value. tive speed changing elements which are brought Also a hydraulic coupling may be regulated in into engagement with each other only at the at- 10 the same manner within a narrower range, i. e., tainment of equal or substantially equal speeds. between the full positive and a small negative With such compound transmissions, itis known fractional value. This simple adjustability of to'arrange between the hydraulic power transthe torque output for equalizing the speeds of mission and the gear change transmission systhe transmission elements to be engaged for eftem a positive coupling which may be made inl5 fecting a speed change is made use of according eil'ective at any desired time in order, when efto the invention by means adapted to move the fecting a speed change, to release the last eiecdisconnecting mechanism into various positions tive speed transmission elements, and to make as required. Such an arrangement makes it posit possible to equalize the speed of the transmissible not only to eliminate mechanical equalizing sion elements to be made effective independently mechanisms and their complicated control sysof the starting speed of the hydraulic system, I tems, but also does away with the arrangement It is also known to employ for this purpose a of a friction clutch between the hydraulic transspecial equalizlng mechanism comprising a frlcmission and the gear transmission. Inv Other tion clutch to produce acceleration and a fricwords, all elements subject to wear are elimi-A tion brake for the purpose of retardation of the nated. transmission elements. When employing a shiftable turbine wheel, the Furthermore, it is known in a hydraulic circuit input of power into the hydraulic circuit remains to interrupt the conveying of power from the priunchanged in the disconnecting position of the mary side to the secondary side by employment disconnecting mechanism, so that the motor reof an annular slide valve or by the shifting of mains unaieted by the COIldtOnS 0n the 011tshiftable blades so that the ow of fluid is imput Side of the hydraulic System and n0 particupeded. It is also possible to interrupt the conlar control of the motor is required. veying of power above referred to by withdrawing With other constructions, for instance, annuthe pump or turbine wheel in an axial direction lar slide valves, a reduction in the power input from the hydraulic circuit. Such and similar deinto the hydraulic circuit may occur when the vices are included in the term disconnecting disconnecting mechanism is in its disconnecting mechanism. position. q

This invention relates to hydromechanical It is, therefore, a further object of the invencompound power transmission systems, in which tion, under such conditions, to prevent variations at least one hydraulic circuit is provided with 4o in -the speed of the motor. This problem is such disconnecting mechanism. solved according to the invention by the provision One of the-objects of the present invention is of means associated with the disconnecting the provision of a hydromechanical compound mechanism for appropriately reducing the supply power transmission, which will make it possible of fuel to the motor.

to eliminate special equalizing' mechanisms here- 45 It is also an object of the invention to provide tofore required in order to enable a proper Change an additional braking effect in cases where the from one speed to another. This problem has normal braking effect of the disconnecting mechbeen solved according to the present invention by anism yin its braking position is not quite sufilstarting from the fact that the ratio between the cient. To this end, according to the invention, primary and SBCOndaIy Speed, at the time Of efthe blade arrangement of the hydraulic confecting a speed change, is such that an axially verter may be Varied so as to cause such an admovable turbine wheel of a torque converter. ditional braking effect. If this is not possible, an when in its fully withdrawn position, not only auxiliary mechanism, for instance, a stationary receives no driving torque but actually receives a blade assembly may be provided for creating a braking torque. This phenomenon is, of course, sufciently great braking torque. y

l mechanism exerts an impulse position," and the position between the in-position and the braking-position, at which no torque is exerted upon the turbine wheel, is designated asthe"neutra1position.

In order to speed up the equalization of the speeds of speed transmission elements to be interengaged, the invention provides means adapted,

during the time required for the said equalization, to maintain the disconnecting mechanism in a definite position between the in-position and the neutral-position.

According to the invention it is also made possible to cause the disconnecting mechanism to move from the neutral-position, either with equal speed, or in the neighborhood of the neutral-position at a lower speed, and then later at a greater speed in order to prevent too fast an increase in speed and the risk of shocks caused thereby.

If desired, according to the invention, it is also possible, during the disconnecting-operation, to brake at the neutral position and to allow movement to the braking-position only when this is required'by the speed change operation'.

It is a further object to provide a simplified control for a hydraulic compound powerv transmission, which will make it possible to eect a speed change merely by adjusting a. pre-selecting lever without further adjustments. This problem is solved according to the invention by controlling the disconnecting mechanism in accordance with the difference between that position of the preselecting mechanism, which is hereinafter referred to as theposition of the clutch sleeve, and the actuallposition of the clutch sleeve, which is hereinafter referred to as the actual-position thereof. The disconnecting mechanism carries out its disconnecting stroke until the control for movement in the opposite direction.

These and other objects and advantages of the invention will appear more clearly from the following specification taken in connection with the accompanying drawings, in which:

Figure 1 is a longitudinal sectional View illustrating a structure according to the invention, which comprises a torque converter With an annular slide valve used as disconnecting mechanism, and a gear change transmission system which has a plurality of gears constantly interengaged, and jaw clutch members adapted to being another additional arrangement which may v be used in connection with the arrangement of Figure 1.

Figure 6 is a longitudinal sectional view of a furtherl embodiment of the invention involving a torque converter with an axially movable turbine wheel, and a gear change transmission system having jaw clutch elements with slant front faces.

Figure 7 is a similar view of astill another embodiment of the invention comprising a hydraulic transmission system with torque converter and hydraulic coupling, the turbine wheel of the latter being provided with shiftable blades, and a gear change transmission system provided with a threaded sleeve supporting the jaw clutch elements.

Figure 8 is a fragmentary detail of Figure 7 showing the parts in a dierent position.

Referring to the drawings in detail, the hydraulic power transmissions shown in Figures 1, 6 and 7 have in common an input shaft I adapted to be driven by a motor, not shown in those iigures. The pump wheel 2 of the hydraulic circuit.

constituting the disconnecting mechanism cooperates with a turbine wheel 3. The output shaft 4 of the hydraulic power transmission constitutes the input shaft to the gear change transmission system, which, merely for purposes of simplifying the drawings, is shown as a two-speed gear transmission system. It is to be understood that the invention is by no means limited to the employment of a two-speed gear transmission and that the gear transmission shown in the drawings may -be replaced by any other convenient system of any desired number of speeds.

Rigidly connected with the output shaft 4 is the gear 5 in constant mesh with the gear 6 rigidly connected to the countershaft '1. The countershaft 1 has rigidly connected thereto a second gear 8 in constant mesh with the low speed gear 9 rotatable with respect to the output shaft I0. The output shaft Ill is axially aligned with the output shaft 4 and is adapted, by means of a clutch, to be connected in direct drive with the shaft 4 through the gear 5 or in indirect drive through the low speed gear 9 and countershaft 1. The directions of rotation of the various shafts are indicatedby the arrows designated 2|, 22, 23 and 24, respectively.

The disconnecting mechanism is actuated by means of a servomotor I3, operating a lever I2 and a slidable sleeve 34. This kind of actuation of the disconnecting mechanism is, of course, merely given by way of example, and it is to be understood that the invention is not limited to the particular structure of the disconnecting mechanism shown in the drawings. It is also possible to connect to the lever I2 a link or link system |60, as shown in Figure 4, which controls ,f

the supply of fuel'to the motor ISI for driving the input shaft I.

The shifting of the sleeve clutch40 along the.

shaft I IJ between the gears 5 and 9 may be effected by a lever I4 which is yieldingly connected with the gear shift lever I5'. The position of the lever.

I4 always represents the actual-position of the clutch, while the position of the shift lever I5 in dicates the a: position of the clutch, i. e., the position which the clutch should occupy at the com- 'i The controlling fluid lfor the servomotor I3 is supplied to the controlling mechanism I by means of a'pressure fluid source, for instance, a

Y drawings as a manually operable lever. it is of course understood that any other kind of shifting element or mechanism may take the place of said manually operable lever.

For example, instead of a manual shift lever, the arrangement shown in Figure 5 may be employed, wherein the output shaft I0 is coupled to a shaft |8Ia having keyed thereto a =bevel gear |62 meshing with a bevel gear |83. The bevel gear |63 is keyed to a rotatable shaft |84 of a governor |85. The governor |85 comprises a collar |86 fixed to shaft |64 and a collar |61 slidably mounted on the shaft |84. The collar |61 has pivotally connected thereto arms I 88 with weights |63, whereas the collar |88 has pivotally connected thereto arms |10 which in their tum are pivoted to the arms |88. A spring |1| inters posed between the collars |68 and |61 continu ously urges the collar I 81 away from the collar |66. The collar I61,has a groove |12 slidably engaged by one arm of a bell crank lever |13, the other arm of which is pivotally connected to the piston 60a which in its construction fully corresponds to the piston 60 of the control mechanism of Figure 1, which is describedhereinafter. As will be clear from the drawing, increase in the speed of the output shaft I0, causes weights |69 to move outwardly, thereby causing lever I1-3 to .move in a clockwise direction so as to eilect a shifting movement of piston 60a toward the right in Figure 5, and the servo-motor is operated accordingly.

Referring again to Figure 1, wherein the gear change transmission system has associated therewith an ordinary torque converter, the fluid flows from the pump wheel 2 to the turbine wheel 3.-

then tothe guide wheel 30 and back to the pump wheel 2.

The disconnecting mechanism of Figure l comprises an annular slide valve 3| which is shown in full lines its inoperative or open position, and in dot and dash lines in its operative or closed position. The slide valve 3| is supported by and connected to the sleeve 34 by means of bolts 33. The sleeve 34 is provided with an annular recess I which is engaged by the lower end of the'lever I2. The torque converter is, as a rule, continuously lled with driving fluid.

In the open. or ineffective position of the annular slide valve 3| the fluid in the converter circulates as indicated by the arrow 35, without being substantially impeded. In the operative or closed position of the annular slide valve 3|, however, the circulation of the fluid between the respectively, and an annular recess 46 engaged by the lever I4. The gear 8 is provided with jaws 41 adapted to engage the .jaws 42 of the clutch, while the gear 8 is provided with jaws 48 adapted to engage the jaws 43 of the clutch. The vhiaw assemblies 41 and 48 have conically shaped recesses adapted to receive the spacer rings 45 and 50, which-have their outer peripheries provided with longitudinally arranged grooves 5| and 52. The spacer rings 48 and 50 are pressed, by

means of springs 53 and 54, against adjacent walls in the conically shaped recesses and are rotatably connected to the shaft I0 by means of the key 4|. It should be noted that the groove 55 in the clutch, as shown in Figure 3, is wider than the key 4|.

Referring now to the controlling mechanism I8, the outer piston 80 vis slidably mounted in the casing 8| and is -pivotally connected with the gearshift lever I5. The inner piston 62, which is pivotally connected to the lever I4, is slidably mounted within the piston 60. The pistons 68 and 82 are yieldably held in a relative position by means of the springs 63 and'64, which predetermined position will hereinafter be called intermediate-position. The'spring discs 85 and 68 respectively abut two shoulders in the bore of the piston 60. The pistons may move relative to each other only by compressing one of the two springs. The compressed spring will then always tend to reestablish the intermediate-position.

The piston 80 is provided with two rows of ports 61. and 68. The piston 62 has two annular recesses 89 and 10 connected with each other by a. passageway 1|. 'I'he casing 8| has two annular recesses 'l2 and 13 respectively connected tothe conduits I1 and I8.

The ports 81 are provided for establishing communication between the recess 12 whichy is connected to the conduit I1 and the annular recess.

duit I1 can then pass to the conduit I8.

wheels 2 and 3 is interrupted, the output shaft 4 can, therefore, receive a torque only insofar vas the annular slide valve 3| is carried around by the fluid acting upon the inside of the valve 3| and circulated by the pump wheel 2;? On the other hand, strong whirls are created between the exit edge 36 of lthe turbine wheel 3 and the entrance edge 31 of the guide wheel, which whirls use up a torque greater than that exerted by the primary side. In the arrangement of Figure 1, the braking effecty will, therefore, as a rule, be sufficient and will not require an` additional braking mechanism, provided the distance between the turbine wheelexit and the guide wheel entrance is not too great.

The servomotor I3 comprises a cylinder 80, a f

piston 8| slidably mounted therein, and a spring 82 acting upon said piston to urge the same toward the left in Figure l. 'I'he cylinderf80 has a discharge port 85 which is small in diameter in comparison to the diameter of the conduit I8.

The device shown in Figures 1, 2V and 3 operates l as follows:

It is assumed that the device is, as shown in the drawings, so adjusted that the low speed is .effective. It is further assumed that the slide valve 32 has been withdrawn to open positionand is maintained by spring 82 in this position. It is also assumed that the clutch 40 isV in its right hand position wherein it engages the jaws 41 of the low speed gear 8 so that the power is conveyed from the shaft 4 through gear 5, gear 8, countershaft 1., gears 8 and 3, jaws 41 and 42, clutch 48 and key 4I tothe shaft I0.Vv

If the levers I4 and I6 are in the position shown in Figure 1, and the pistons 6I! and 62 of the control mechanism are in the intermediate-position, it is desired to .shift from the iirst to the second speed, i. e., from low speed to high gear, 5

the lever I5 is moved into the position indicated by the dot-and-dash line I8. Due to this shifting of the lever I5, the piston 60 moves toward the right and causes a-compression of the spring 84, while the position of the piston 62 at first remains unchanged because the thrust of the spring 64 is not suilicient to disconnect the jaws 42 and 41 of the clutch 40 since the Jaws 4,2 and 41 are still:

pressed against each other by the torque imposed upon said jaws. However,v inasmuch as the pistons 60 and 62 have moved relative to each other. the ports 68 have moved past the controlling edge 14 toward the right, thereby establishing hydraulic connection between the conduit l1 and the servomotor |3-fthrough the conduit I8.

This causes the piston 8| to move toward-the right while the lever I2 moves into the position indicated by the dot-an'd-dash line 20. Because of the connection of the piston 8| with the annular slide valve 3| b y means of the linkage 83, I2 and the sleeve 34, the slide valve 3I moves toward the left to its closed position and interrupts the circulation of the fluid in the converter. Before the piston 8| completed its stroke, the slide valve 3| reaches its neutral-position. .At this instant the clutch jaws 42 and 41 are relieved of their load. l

The sleeve 40 in being moved toward the left by the thrust of the spring 64 can move only until the outer face 56 ofthe extension 45 en gages the outer face 51 of the spacer ring 50. The reason for this is that in rst gear speed shaft I rotates with a yspeed lower than that kof the high speed gear 5. During the shifting operation, at about the intermediate-position of the clutch 48, the spring 54 has become loaded, so that the spacer ring 50 is pressed against the gear 5. The gear has the tendency, due to friction between the gear 5 and the spacer ring 50, to carry the latter around. This, however, is possible only to a limited extent, i. e., until the side'58 of the groove 55 abuts the key 4i.

In this position of the spacer ring 50, the groove 52 has moved into a position opposite to the extension 45 on the clutch 40 and the outer faces 56 and 51 of the spacer ring 50 and the clutch engage each other. Simultaneously, the piston 62 is moved toward the intermediate-position by about two-thirds of its entire stroke. With the pressure fluid, still passing by the lcontrolling edge 14 to the conduit I8, that the piston 8| moves to the extremev right and the annular slide valve 3| is thereby moved into its fully closed position. As a result, the braking eifect of the blade edges 36 and 31 becomes effective, whereby the speed l of the shaft 4 is reduced.

` When the speed of rotation of the shaft 4 and of the output shaft I0 are about equal, or if the rotating speed of the shaft 4 begins to become less than the rotating speed of the output shaft I0, the spacer ring 50 is carried around in the opposite direction. At the moment at which the ring 5U moves relative to the clutch 40 to the position shown in Figure 3, the extension 45 passes into the groove 62 and the :laws 43 and 46 become engaged with each other.

As the clutch 40 moves into its extreme lefthand position and the lever I4 moves into the position designated by line 25, the two pistons 64 and 62 again reach their intermediate-posiarcano tion, and the :l2-position and actual-position 'of the-clutch become the same, so that the disc 6l 'I'he fluid in the cylinder of the servoxnotorl I3 is discharged by the thrust oi' the spring 32 'which forces the fluid out through the opening lo 85. The piston 8| is returning to the position Jshown' in Figure 1, returns the annular valve 3| to its open position, shown in Figure 1. As a result. the converter again. conveys a torque through the output shaft 4, gear 5, jaws 46 and 43, clutch 40 and key 4I to the shaft I0.

The opposite shifting operation, that is. from high speed to low direction, i. e., from higher speed to lower speed gear is eiected substantially in the same manner. It differs from the shifting operation described above only in that after the declutching of the previously engageddaws 43 and 48, and after engagement of the spacer ring 49 by the clutch 40, passage of fluid through the ports 68 is interrupted by the controlling edge 15, thereby initiating the opening movement of the annular valve 3|. The reason for this is that,

in order to obtain equalization, the speed of rol tation of the shaft 4 must be increased with respect to its previous speed. In other words, the braking eiect, when the annular valve 3| has reached its fully closedV or effective position, is not made use of. As soon as equalization has been obtained, the jaws 42 and 41 again engage each other and the further increased torque is conveyed through the countershaft 1 to .the shaft I0.

Only one embodiment has been described for hydraulically actuating the slide valve 3| by means of the controlling mechanism I6. It should, however, be noted that, if desired, the piston 8| could be hydraulically controlled in both directions by providing two conduits .between the controlling mechanism I6 and the servomotor I3. The pistons 6I! and 62 would then be so constructed as to also control also the returning uid.

Referring now to Figure 6, the embodiment shown therein likewise comprises a, gear change transmission system in connection with an ordinary Atorque converter. This torque converter also comprises three blade assemblies involving the pump wheel 2, turbine wheel 3, and the guide wheel 30, respectively, The disconnection of the power transmission in this embodiment is effected by withdrawing the turbine wheel 3 from the hydraulic circuit by moving the turbine wheel in axial direction. To'this end the hub 90 supporting the disc 9| of the turbine wheel a, is

slidably mounted on the shaft 4 but is prevented from rotating relatively to the latter. The hub is provided with an annular recess II slidably engaged by the lever I2. In this arrangement also the converter is, as a rule, filled with driving fluid. As long as the input or driving shaft I rotates, fluid is rotating in the converter in the direction indicated by the arrow 35.

. When the turbine wheel 3 is in the operative position shown in Figure 6, it is acted upon by the circulatingA fluid and, therefore,fconveys a torque to the shaft 4. However, when the turbine wheel 3 is in its inoperative or withdrawn position, indicated in dot-and-dash lines in Figure 6, substantially no torque is conveyed to the output shaft 4.

Since the friction on the wall of the converter one and filling another hydraulic circuit.

elements is, as a rule, not sufficient to cause a fast decrease in the'speed of shaft 4, a stationary auxiliary blade assembly 32 is provided, which is located opposite the blades of the turbine wheel 3 when the turbine wheel is 'in its inoperative position, so as to exert a braking torque upon the turbine 3 and, thereby, upon the output shaft 4. The employment of such a converter with slidable turbine wheel has the particular advantage that the circulation of the fluid in the converter continues, and that the motor, during the entire shifting operation, still may continue to exert its full power upon the pump wheel so that which, by means-of intermediate plnions ||0 arranged on the secondary wheel 3, mesh with the gear ||1 which is rotatably mounted on the shaft 4 but is prevented from moving axiallyv relative to the shaft 4.

The hub of the gear ||1 is provided with s, thread H8 adapted to mesh with a corresponding thread in the sleeve ||9, which is provided with an annular recess slidably engaged by the lever |2. The sleeve ||3 is mounted on the shaft 4 so as to be axially movable relative thereto,

no variations Ain its speed of rotation occurs.-

The shifting operation of the gear change transmission system is effected by a two-side spacer clutch of well known type.

The durch lou is longitudinally sudabie on" the shaft 0 but prevented from rotating relative thereto. The clutch |00 is provided with two rows of jaws |0| and |02 with slant front faces. The front faces of the jaws |03 and |04 provided on the gears 9 and 5 are similarly inclined, this arrangement being provided for preventing meshing of the jaws until the speeds of the elements to be interconnected vhave been equalized.

Since the controlling 'mechanism I6 and the servomotor I3 of Figure 6 are supposed to be of the same construction as that shown and de scribed in connection with Figure 1, the gear yshifting operations are effected in the manner as described above in connection with Figure 1. The function performed by the 'spacer rings in Figure l is performed by the spacer surfaces or slant front faces of the jaws |0|, |02, |03 and |04. When the jaws |0| are disengaged from the jaws |03, the front faces of the jaws |02 and |04 slide upon each other as long as the turbine wheel 3 runs faster than the shaft |0. The clutch ratchets. When equalization of the speeds of rotation has been obtained, or the speed of the shaft |0 slightly exceeds that'of the shaft 4, the

slant surfaces act in the reverse direction and cause the jaws |02 and |04 to mesh with each other.

In Figure 7 is shown an embodiment consisting of a compound power transmission which comprises two mechanical and two hydraulic speeds. The hydraulic power transmission system comprises a torque converter with pump wheel ||0, turbine wheel and guide wheel ||2, and further comprises a hydraulic coupling with pump wheel 2 and turbine wheel 3. The shifting of the hydraulic circuits is effected by discharging The mechanical gear change transmission system illustrated in Figure 7 also has two speeds. although, as previously mentioned, a mechanical gear change transmission with more than two speeds may be used. The shifting of the said gear change transmission is intended only when the hydraulic coupling is lled, The compound power transmission may, therefore, be operated selectively in anyv one of the following combinations:

1. Torque converter, first speed, 2. Coupling, nrst speed, 3. Coupling, second speed.

blade pivots ||4 are provided with pinions lli 'uy from the reader.

but is prevented from rotating relative to the' shaft 4. y

Figure 7 shows the shiftable blades I 3 in their inoperative position, whereas Figure 8 shows the blades ||3 in their operative position. The coupling has no stationary partsvso that no braking effect can occur therein. However, ythe coupling eect cannot be completely eliminated, since whirls occur on the blade edges ||9a, |20, |2| and |22, which cause rotation of the couplingl elements toacertain extent.

Therefore, according to the invention, additional braking means is provided by mounting on the rotating casing 0f the coupling a blade wheel |23 for a small hydraulic brake. Opposite to the wheel |23 there is located a blade assembly |24 which is fixed with respect to the guide wheel |2 and is surrounded by the rotatable annular portion |25. In normal operation, the channel denedby the elements |23, |24 is empty. During the speed shifting operation of the gear change transmission system, when the hydraulic circuit is interrupted, the braking mechanism is provided lwith uid from the coupling.- the fluid passing through grooves |28 inthe blade pivots ||4 and through bores |21 in the coupling casing when the pivots are turned to the proper position. The blade pivots I4, therefore, act as shiftable valves.

AWhen, during the shifting operation, the blades ||3 are returned to their inoperative position, the

admission of fluid to the brakemeans is interrupted so that the same is emptied through the bores |28.

Another braking arrangement is indicated in dot-and-dash hnes in Figure 7, wherein the sleeve ||0- may be provided with a braking disc |29, while a yielding member is interposed between the sleeve ||9 and the disc |29. The disc |23 is adapted in the right hand position of the sleeve H3 to engage a. brake surface |30 in the casing, to produce the desired braking action.

The clutch for effecting the speed change lin the gear change transmission system is shown in Figure 7 as an automatic clutch of a. well known type wherein only the locking of the clutch is controlled from the outside. Mounted on the shaft |0 is a. thread |40 with high pitch which engages a corresponding thread lin a sleeve |4|.

The sleeve |4| is provided with a jaw assembly |42 and two pawls |43 and a tooth |45. The jaw assembly |42 is adapted to mesh with the jaw assembly |46 on the gear 9 or with the jaw assembly 41 on the gear 5. The pawl 43 has its point directed toward the reader. In the intermediate-position of the sleeve |4|, the pawl |43 is located opposite the jaw assembly |41. If the jaw assembly |41 runs faster than the shaft I0, the pawl |43 will ratchet. If thejaw assembly |41 runs slower than the shaft I0, the pawl |,43 comes into operation and causes the sleeve |4| to move into its leftl end position. The pawl |44 is associated with the jaw assembly |46 and has its point 'directed away As long as the gear 3 runs |44, as well as with I0, the pawl |44 comes into operation and pulls the sleeve into the extreme right hand position. The locking sleeve |48 with its teeth |49 slides on the teeth |45 of the sleeve |4I. Furthermore connected to the shaft I is the hub |50, which is provided with locking teeth. Bolts |52 engage the annular groove |Iof the locking sleeve |48. The bolts |52 are connected to the sleeve |53 and extend through slots formed in the cylindrical portion carrying the jaw assembly |41. The sleeve |53 itself is shifta'ble by means of the lever I4 which engages an annular groove in the sleeve. m

The shifting from low gear to high gear, the parts being in the position shown in Figure 7, is effected as follows:

When the gearshift lever I5 is shifted toward the right, the locking sleeve |48, with sleeve |53 and lower lever portion I4, immediately moves toward the left until the front face of the teeth |49 abuts the rlght'front face of the hub |50. The servomotor |3- then receives uid through the controlling mechanism I6 and the lever I2 and, with the latter, the entire mechanism including the blades ||3, move into a position for interrupting the hydraulic circuit, whereby the power transmission is interrupted and the channel I23, |24 of 'the hydraulic braking means is lled with uid.

Due to the resultant braking torque, the sleeve |4I threads itself into intermediate position and the pawl |43 ratchets on the jaws |41. At this time, the gear 5 still moves faster than the shaft l0. When the speed of the gear 5 has been decreased by means of the brake to such an extent that the gear 5 starts moving slower than the shaft I0, the pawl |43 becomeseflective and pulls the sleeve I 4| toward the left until the jaws |42 andY |41 mesh, in which position the teeth |49 engage the teeth |50 and the sleeves |48 and |53 move toward the left, and the lever I4 occupies 1. In a hydromechanical compound power transmission system, a torque converter comprising a pumping blade assembly, a turbine blade assembly and a guide wheel blade assembly, a

mechanical power transmission having a plurality of speed transmitting elements, an output shaft drivinglyconnected to the turbine blade assembly of said converter and also drivingly connected to the input side of said mechanical power transmis-- sion, mechanical means for selecting two transmitting elements for driving engagement with each other, a braking blade assembly, and meansk operated by said mechanical means for moving said turbine blade assembly into a position for.

`transmitting elements, an output shaft connected to said coupling for conveying power from said coupling to the input yside of said mechanical power transmission, a rst bra'ke element con- L nected to said coupling, a second brake element operatively connected to said mechanical power the position indicated by the dot-and-dash line l The pistons of the controlling mechanism I6 then return to their intermediate position and the servomotor I3 is without pressure. The lever and the blades |'I3 and valve pivots I|4 return to open position. Torque is then conveyed through shaft 4, gear 5, jaws |41 and |42, sleeve |48 and hub |50 to the shaft I0.

In changing from high gear to low gear is effected, the lever |4 does not at once follow the lever |5 because the locking sleeve |48 is loaded by the torque. I

. I2 returns to the position shown in solid lines Only when the torque becomes substantially Y zero by movement of the blades I|3 into eective or interrupting position, does the locking sleeve |48 jump out, but at this time cannot yet occupy thev position shown in solid lines in Figure 7. As described in connection with Figure 1, the servomotor |3 lbegins at this point to lose its pressure so that the valve blades I|3 open again. As a result, the shaft 4 begins to accelerate and, at the attainment of substantial equalization of the speeds of shafts 4 and I0, all parts again occupy the positions shown in Figure 7. t It will be understood that we desire to comprehend within our invention such modifications as come within the scope of the appended claims.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent is:

transmission, mechanical means for selecting two transmitter elements for driving engagement with each other in correspondence to a. desired speed, means for interrupting the coupling'effect of said coupling, and means responsive to the operation of said mechanical means for engaging said brake elements with each other to bring about a slowdown movement of said output shaft for a speed equalization'of the transmitter elements to be connected with each other.

3. In a hydromechanical compound power transmission system, a hydraulic torque converter comprising a pumping blade assembly, a turbine blade assembly and a stationary guide wheel, a brake blade assembly rigidly connected to said guide wheel but mounted outside the path of fluid within said guide wheel and said pumping blade assembly, a mechanical power transmission having a plurality of speed transmitter elements, mechanical means for selecting two of said speed transmitter elements for driving engagement with each other in accordance with the desired speed, an output shaft for conveying power from said converter to the input side of said mechanical power transmission, means drivingly connecting said turbine blade assembly to said output shaft and being axially slidable on said output shaft andv control means operated by said mechanical means for selectively moving said turbine blade 7 assembly into the path of circulating fluid in said converter or out Vof said path into cooperation with said brake blade assembly for slowing down the rotative movement of said output shaft tol cause a speed equalization of the speed transmitter elements to be engaged with each other.l

4. In a hydromechanical compound power transmission system, a hydraulic power transmission including a hydraulic coupling, a mechanical power transmission having a plurality of speed transmitting elements, mechanical means for selecting two of said transmitting elements for driving engagement with each other in accordance with a desired speed, an output shaft drivlngly connected to said coupling and to the input side of said mechanical power transmission for conveying power from said coupling to said mechanidown the rotative movement of said output shaft for a speed equalization of the transmitting elements to be drivingly engaged with each other, said control means also being operable selectively to interrupt hydraulic connection between said coupling and said brake for making the former effective and the latter ineffective.

5. In a hydromechanical compound power transmission system, a hydraulic transmission, a mechanical change-speed transmission having a plurality of speed transmittingelements, an output shaft connected to the output side of said hydraulic transmission for conveying power to said mechanical change-speed transmission, control having a first member movable into a plurality of positions corresponding innumber to the available speeds in said compound power transmission and operable for selecting two of said transmitting elements for driving engagement with each other to provide a desired speed ratio, said Vcontrol means having a second member movable for effecting driving connection between said selected transmitting elements, the position of said second member corresponding to the actual condition in said mechanical changespeed transmission and the position of said first member indicating the desired condition in said mechanical change-speed transmission, said control means having a third member associatcdwith said hydraulic transmission and movable selectively into one position for slowing down the movement of said output shaft to cause a speed equalization of the speed transmitting elements for engagement with each other, and means responsive to a diiference between said actual and said desired condition in said mechanical changespeed transmission for initiating movement of said third control member to enect a speed equalization between the speed transmitting elements to be connected with each other.-

6. In a hydromechanical compound power position of said second member corresponding to the actual condition in said mechanical changespeedtransmission andthe positionofsaidiirst member indicating the desired condition in said mechanical change-speed transmission, said control means having a third member associated with said hydraulic transmission and movable selec-l tively into one position for slowing down the movement of said output shaft to cause a speed equalization of the speed transmitting elements for engagement with each other, means responsive to a difference between said actual and said desired condition in said mechanical changespeed transmission when a shifting operation from a higher to a lower speed is desired for initiating movement of said third member to effect a slow-down movement of said output shaft for a speed equalization of the speed transmitting elements to be engaged with each other, and meansy responsive to an agreement of said act'ual condition with said desired ,condition following initiation of a speed shifting operation fromy a lower speed to a higher speed for preventing said third control member from slowing down said output shaft following the disengagement of the transmitting elements preceding the driving engagement of the selected transmitting elements.

7. In a hydromechanical compound power transmission system, a hydraulic transmission, a mechanical change-speed transmission having a plurality of transmitting elements. an output shaft connected to said hydraulic transmission for conveying power to said mechanical changespeed transmission, a sluiting element in said $5 mechanical change-speed transmission for eecting a driving engagement between two desired transmitting elements, control means having a first member movable into a plurality of positions corresponding in number to the number of 40 available speeds in said mechanical change-speed transmission system, a hydraulic transmission, a

mechanical change-speed transmission having a plurality of speed transmitting elements, an output shaft connected to the output side of said hydraulic transmission for conveying power to said mechanical change-speed transmission, control means having a nrst member movable into transmission, the position of said first member corresponding to the desired position of said shifting element, said control means having a second member for actuating said shifting element, the position of said second member correi subsequently to be engaged, and means responsive to the initiation of a shifting movement from a higher speed to a lower speed for making said third control member ineffective immediately following disengagement of said transmitting elements to be disengaged.

HEIMUT BENZ. FRITZ KUGII 

